NAME

       qbrb.h - This implements a ring buffer that works in "chunks", not bytes.

SYNOPSIS

       #include <qb/qbrb.h>

DESCRIPTION

       So  you  write/read  a  complete  chunk or not at all. There are two types of ring buffer:
       normal and overwrite. Overwrite will reclaim the oldest chunks inorder to make way for new
       ones, the normal version will refuse to write a new chunk if the ring buffer is full.

       This  implementation  is  capable  of  working across processes, but one process must only
       write and the other process read.

       The read process will do the following:

            rb = qb_rb_open("test2", 2000, QB_RB_FLAG_SHARED_PROCESS|QB_RB_FLAG_CREATE);
            for (i = 0; i < 200; i++) {
       try_read_again:
               l = qb_rb_chunk_read(rb, (void *)out, 32, 1000);
               if (l < 0) {
                       goto try_read_again;
               }
            }
            ...
            qb_rb_close(rb);

       The write process will do the following:

            rb = qb_rb_open("test2", 2000, QB_RB_FLAG_SHARED_PROCESS);
            for (i = 0; i < 200; i++) {
       try_write_again:
               l = qb_rb_chunk_write(rb, &v, sizeof(v));
               if (l < sizeof(v)) {
                       goto try_write_again;
               }
            }
            ...
            qb_rb_close(rb);

SEE ALSO

       qb_rb_close(3), qb_rb_refcount_get(3), qb_rb_chmod(3), qb_rb_chown(3), qb_rb_open(3),
       qb_rb_write_to_file(3), qb_rb_create_from_file(3), qb_rb_chunks_used(3),
       qb_rb_chunk_reclaim(3), qb_rb_space_used(3), qb_rb_chunk_write(3),
       qb_rb_shared_user_data_get(3), qb_rb_chunk_commit(3), qb_rb_chunk_peek(3),
       qb_rb_space_free(3), qb_rb_name_get(3), qb_rb_chunk_alloc(3), qb_rb_chunk_read(3)

COPYRIGHT

       Copyright (C) 2010-2020 Red Hat, Inc.